Vertically slidable closure



July 30, 1940- N. R. GUILBERT. JR

VERTICALLY SLIDABLE CLSURE Filed Nov. -2.2, 1937 HTTOENEY Patented July 30, 1940 UNITED STATES ywlTENTf oFFlcE VERTICALLY sLIDABLEy OLO-SURE Nicholas R. Guilbert, Jr., Chestnut Hill, Pa. Application November 22, 1937-,l serial No. 175,791

`4 claims. (c1. .2o-fic) This invention relates to improvements in vertically slidable closures and is of special advantage in dumb-waiter doors and the like in which a relatively heavy door must be raised and lowf- `5 ered by hand as it is directed primarily to improvements in supportingmechanism for such doors or other'closures whereby the facility with which they may be raised and lowered is materially enhanced.

It is the practice to counterbalance the weight of doors of this class either by counterweights or by spring balances to enable the operator to open the door without actually lifting its entire weight and also to prevent it from falling shut l5 again after it has been opened, and'mechanism embodying my invention is particularly adapted for association with such doors counterbalanced by means of spring balances as it provides means whereby the counterbalancing springs may be readily and quickly adjusted to insure a proper suspension of the door and thereby prevent it from sticking kthrough unequal tension of the springs on its opposite sides.

It is therefore a principal object of the invention to provide, fin combination with a dumbfwaiter door or other vertically slidable clo'- sure and counterbalancing mechanism therefor, means adapted to facilitate adjustment of such mechanism to insure equal counterbalancing of the opposite sides of the door, as Well as to compensate for slight inequalities therein whereby the door is afforded equal support from its opposite sides and the ease with which it can b raised and lowered thereby enhanced. l

Another object of the invention is to provide improved anchoring mechanism for the fixed ends of dumb-waiter door counterbalancing means whereby the tension of each ofsaid means reacts against that of the other so that they 40 are maintained in equilibrium with respect to the door to cause the latter to travel smoothly on its ways or tracks.

Other objects, purposes and advantages of the invention will hereinafter more fully appear or will be understood from the following description of a preferred embodiment thereof as illustrated in the accompanying drawing.

In the said drawing Fig. 1 is a fragmentary front elevation of the assembled dumb-waiter door mechanism removed from the hatchway.

Fig. 2 is a vertical section thereof on the line 2 2 in Fig. 1. 1

Fig. 3 is a fragmentary view on an enlarged scale, partially in plan and partially in horizonconstituting the top, door. This door is arranged to'slide vertically vto guide the door.

ltalsection principally on line 3-3 inFig. 1,

showing the said mechanism applied to a typical dumb-Waiter hatchway.

Fig. 4 is a fragmentary enlarged detail of a portion of Fig. 2 in which'the door is shown in 5 raised position. v

In the several figures like characters are used to designate the same parts.

Referring now more particularly to theV drawing, the door I, preferably made of sheet metal, 10 is rectangular in shape with its side edges turned at right angles to itsr general plane to form edge surfaces of substantial Width, thereby giving the door the form of a shallow tray, the turned edges bottom and sides of the 15 in the dumb-waiter hatch, the plane of the inside of the front wall of which is indicated by the lineA W in Fig. 2, and has secured to each `,of its sides adjacent the top and bottoma pair..-20

of track engaging shoes 2 adapted to receive one flange of an angle rail forming a track 3 which extends from the bottom of the hatch opening to a point appreciably above its top and serves The lower portions of tracks -25 3 at the sides of the hatch opening are secured to the walls W of the hatchway by bolts 4 which support them from angle vrails 5 xed in any suitable manner Yto the said walls while the upper parts of the tracks have angle brackets 6 30 fastened tothem and to the wall to afford them additional lateral support. At the lower cor- -ners of the door are secured a pair of plates 8 which extend beyond the sides of the door for attachment of the spiral steel ribbons 9 of the spring balances I0 which counterbalance the weightlof the door;

These balances are of a usual form well known inf the art and each comprises a relatively long metal tube Il with its upper end anchored in a 40 manner hereinafter described, enclosing a coil spring secured at its upper end inside the top ofthe tube and at its lower end to a rotatable bushing in the latter. The spiral ribbon 9 is slidable in a corresponding spiral slot in this bushing so that when the door is lowered the spiral form of the ribbon causes the bushing to rotate in a suitable direction to load the spring .and thus place it under tension and in condition to assist subsequent raising of the door, l50 during which the bushing turns in the opposite direction under the influence of the loaded spring. Spring balances of` this character are in general use and the specific form of balance employed constitutes no part. of the invention 55 so its details of construction and certain of the parts just described are not shown in the drawing but will be readily understood by those skilled in the art.

The upper ends of tracks 3 are rigidly interconnected by a cross bar I2 which serves to hold them in properly spaced relation and the spring balances Il) are connected with and suspended from this bar as now to be described.

An angular beam I5 extends substantially horizontally adjacent bary l2 and is pivoted to it on a bolt I8 in such a Way as to support the beam from the bar to permit its limited oscillationl in a vertical plane. The beam ends terminate just short of the upper ends of spring balance tubes H and respectively supportv substantially similar plates Il which are secured as by screws I8 or in any other suitable Way to the top ange of '.the beam and project oppositely outwardly beyond its ends. Each of these plates is provided with a circular hole`20I-through which the'upper end of theadjacent tubev Il extends and the latter is suspended from .theplate on Va-pin 2| passingy through a `transverse holel in the tube andl overlying. .the top `of the'plateL As adjustment of the balances is eiiected-bylturning the tubesl relatively toY theirzf-enclosed bushings, to increase or decrease -thespring tension itis essential tovprevent them from turning after proper adjustment hasbeen made and further essential that the pins be keptin' place in order to properly support the -balances from the beam, and to this endlsuitable.f'means are provided consisting, in Athe Vembodiment or thev invention shown, oigan-eye formed at one end of each pin 'and a screw: 212 extendingtherethrough and intothe` subjacentplate il; thus, when vthe screw 'is removed. the tub'eican-beturned` to any desired extent and .thereafter held against turning by threading the screwinto the plate through-the eye which also 4secures the kpin inlplac'e;

In addition..to the? supportingY and guiding meansv just described the door is provided ywith a handle lwhich extendsfvertically adjacent its lower edge-.and has. rubber` or other resilient bumpersl 2t, El projecting,fromitsopposite ends. The bumper-2Gpreierably extends slightly .below the adjacent lower edge of the door for engagementwith the sill' 28 4of the hatch openingwhen thedoor islowered, while thefbumper 2'!v on Vthe top of the handle yis'adapted for similarengagement with the header'v 30'of the hatch opening when the door-is raised, these'bumpers'thus constituting resilient stops to bring Athe door to rest at the iiniitsi of its travel andas they are xed on the door handle with' the latter in vertical position they also effectively! preventthe hand oi the operatorlb'eing crushed against either the sill orthe vheader by the handle while closing or opening the door. Y Y

The mechanism just described affords a facility oi adjustment of the balancing springs which materially simplifies the installation of the door in proper operating condition, while of course readjustment after installation can as readily be made when and if necessary.

Thus as the relatively iixed ends o-f the spring 'balances are supported from a substantially horizontally extending beam pivoted at its center and adapted for oscillation in a vertical plane, it is evident that it can easily be recognized by the horizontal position of .this beam when anvequalized adjustment 'of the balances'has been effected, since if one balance is too" tightly adjusted with 'respectto the other thebeam will be moved on its pivot'so as to tilt toward the too tightly adjusted balance. The beam thus indicates at all times Whether either balance needs adjustment and, if it does, the nature of the adjustment required; that is, if the beam is tilted toward the right in Fig. 1 it indicates the right hand spring balance should be relieved of some of its tension or the tension of the left hand balance increased to thereby equalize the tension the balances respectively exert upon the door. It is usually desirable to have some lateral play between shoes 2 and tracks 3 to enable the door to slide freely, and consequently when the balances vare properly adjusted, beam l5 can oscillate slightly on its pivot in response to any resultant slight lateral movement of the door while it is being raised or lowered; the pivotal mounting of the beam thus always maintains the balances in exact and correct relation to the door to prevent it from sticking or jamming against the tracks.

" f Furthermoregifafter proper initial adjustment the' balances! should in time exert unequal force onloppositelfsides o'f the door, due to unequal stretching of' thesprings or for lany other reason,

the 'inequalitywill-result in tilting beam l5 toward the balance vexertingthe greater force, thus aiTording-a readily observable visual indication "of 'the needfor yreadjustment which can then be promptly eiected after removing one or both screws 22. l" I y n While I'have hereindescribed a preferred embodimentofthe invention as it may be incorporated'ina dumb-waiter door assembly of a type well known in the art, it will be understood that the invention is not limited or confined thereto or toemployme'nt solely in association fwith'dujmb-'waiter doors as mechanism constructed inaccord'ance therewith may advantageously 'bevutilize'd infassociation with vertically slidable closures of various character, while changes and :.modi'fications'the form, construction and ar- -rangement of the severalparts will readily occur to those skilled in the artV and may be made if clf-sired.,y without departing from the spirit and vscopewofk :theinvention as defined in the appended claims.

n describedjmy invention, I claim yanddesiretoprotect by Letters Patent of the United States.. y

.l 1.1In combinationipwith a vertically slidable closure, counterbalancing means t supporting the l closure romits opposite sides, a pivoted substantially horizontal beam disposesd above the clofsure, and meansfor supporting the counterbal- `ancing means from the opposite ends of said beam. t, Y

2,Y In combination with a slidable closure, guide AVshoes carried vby the closure, vertical tracks extending adjacent its opposite sides respectively .adapted to receivesaid shoes, .a cross bar extending between the tracks above the upper limit o1 `travel of the closure, a rigid beam pivoted adjacentV the center of the cross bar for oscillatory movement in a vertical plane, and counterbal- -ancing means for the closure'extending between the respective' ends of the beam and the corresponding lateral extremities of the clo-sure.

disposed above the closure, a' pair of spring balfances eachcomprisin'g a tubular member and a relatively movable closure supporting element connectedlto--the-closure, and means for suspendlingltheV tubular' members adjacent opposite ends 75 of the beam and restraining them from axial rotation.

4. In combination with a vertically slidable closure, a beam disposed above the closure and pivoted at its midpoint for vertical oscillation, a

spring balance adjacent each end of the beam comprising a part projecting through and rotatable with respect to the beam and a subjacent ytransversely through said projecting part above the'beam having an eye at one of its ends, and

-a screw passing through said eye and into the beam preventing longitudinal displacement of the pin from said part and restraining the latter from axial rotation.

` NICHOLAS R. GUILBERT, JR. 

